Sekundärbedarf
Also: sekundärer Bedarf, Sekundärbedarfe, abgeleiteter Bedarf, Komponentenbedarf
AI-generated
Secondary demand refers to the demand for assemblies, individual parts, and semi-finished goods that is mathematically derived from primary demand. The basis for its determination are bills of materials, which specify which components are required to manufacture a finished product.
Key facts
- Secondary demand is calculated from primary demand through bill of materials explosion and forms the basis for procurement and production planning.
- MRP runs in ERP systems automate the determination of secondary demand and derive purchase proposals or production orders from it.
- The quality of bills of materials and inventory data is decisive in determining whether the calculated secondary demand actually matches real demand.
- Secondary demand differs from tertiary demand, which encompasses auxiliary and operating materials that do not go directly into the finished product.
What is secondary demand?
Secondary demand is the quantitative demand for assemblies, individual parts, and semi-finished goods that results directly from primary demand. While primary demand describes the demand for saleable finished products, secondary demand forms the next level of the demand pyramid: it specifies what must be produced internally or procured externally in order for the planned quantity of finished products to be manufactured at all. It must also be distinguished from tertiary demand, which encompasses auxiliary and operating materials such as lubricants or packaging materials that do not directly enter into the finished product.
How is secondary demand determined in practice?
Secondary demand is typically calculated via an MRP run (Material Requirements Planning) in the ERP system. The starting point is the planned production quantities from sales planning or confirmed customer orders. The system resolves these quantities using the stored bills of materials and calculates which components are needed in what quantity and at what time. Existing stock levels and already initiated purchase orders or production orders are offset against this, so that ultimately only the net demand that still needs to be covered is reported.
The quality of master data is critical here: incorrect bill of materials positions, wrong scrap rates, or outdated inventory information lead to incorrect secondary demand quantities and, consequently, to shortages or excess stock. In practice, therefore, close coordination between engineering, production planning, and warehouse management is essential.
- Bill of materials explosion: Multi-level products require a multi-level explosion, in which assemblies are in turn broken down into their sub-components.
- Inventory netting: Existing stock levels and open incoming orders are subtracted from gross demand to determine net demand.
- Scheduling: Order trigger or production start dates are derived from the requirement date and replenishment lead times.
What matters in planning?
For inventory planning, secondary demand is the central driver of stock decisions for C-parts and purchased parts. Knowing secondary demand enables safety stocks to be sized in a targeted manner rather than built up across the board. For purchasing, it provides the basis for supplier scheduling and for the early identification of bottleneck situations.
Depending on the vendor, ERP systems differ in how flexibly they process planning scenarios or multiple bills of materials. The question of whether secondary demand is derived purely deterministically (from orders) or partially stochastically (from forecasts) also varies depending on the industry and production type. In make-to-order production, deterministic explosion predominates; in series production, forecast-based demand is frequently added.
Related terms
- Absatzplanung
Sales planning refers to the systematic forecasting of future sales volumes for defined products, regions, or channels. It forms the foundation for all downstream planning processes in production, procurement, and logistics.
- Absatzprognose
The sales forecast estimates future demand for products or items over a defined period. It forms the basis for inventory, capacity, and procurement planning in logistics and purchasing.
- Bedarfsermittlung
Requirements planning refers to the systematic process by which an organization's future material or goods requirements are determined in terms of quantity and timing. It forms the basis for inventory management, procurement, and warehouse planning.
- Bedarfsmenge
The demand quantity refers to the quantity of an item required at a specific point in time or within a planning period. It forms the basis for ordering decisions, inventory planning, and production planning.
- Bedarfsplanung
Demand planning refers to the systematic process by which a company determines what quantities of materials, goods, or resources are needed and when. It forms the foundation for inventory management, procurement, and warehouse planning.
- Beschaffungsplanung
Procurement planning refers to the process by which a company systematically determines which materials or goods need to be sourced, in what quantities, at what time, and from which suppliers.
- Bestandsführung
Inventory management refers to the system-supported administration and continuous updating of all warehouse and material stocks within a company. It forms the basis for planning, procurement and accounting – and ensures that the book inventory and physical inventory are in agreement at all times.
- Bestandsmanagement
Inventory management refers to the systematic planning, control, and monitoring of stock levels across the entire supply chain. The goal is to ensure delivery capability while keeping capital commitment and warehousing costs within economically viable limits.
- Disposition
Disposition refers to the operational planning and control of resources, quantities, and orders in logistics – for example in transport or materials disposition. It encompasses capacity assignment, scheduling, prioritization, and response to disruptions.